Karnataka on Thursday decided to file an 'original suit' and a Special Leave Petition in the Supreme Court challenging the February 5 final award of the Cauvery Water Disputes Tribunal besides seeking clarificatory orders from the tribunal.

The state Cabinet, which met in Bangalore, resolved to file an original suit under Article 131 of the Constitution and an SLP under Article 136 of the Constitution contesting the tribunal's final verdict, Home Minister M P Prakash told reporters in Bangalore.

Under Section 5 (3) of the Inter-State River Water Disputes Act, a petition seeking clarifications and guidance on its order would also be filed before the tribunal, which allocated 270 tmc ft of water to Karnataka, besides directing it to ensure release of 192 tmc ft of water annually to Tamil Nadu, which gets a share of 419 tmc ft in the Cauvery system.

The tribunal has allocated 30 tmc ft of water to Kerala and nine tmc ft to Puducherry, the other two riparian states in the Cauvery basin.

"The decision to file original suit, SLP and for clarificatory orders stemmed from the advice given by counsels who represented the state before the tribunal and also on suggestions mooted by state's Advocate General Udaya Holla, who was called to the Cabinet meeting," Prakash said.

The issues related to utilisation of underground water and the direction to release 21 tmc ft of water from Kabini, and Kerala's share to Tamil Nadu would be raised before the tribunal, he said.

Karnataka has objections to the tribunal imposing a burden of 10 tmc ft of water for environment protection as the state was of the opinion that water evaporation takes place in its areas also, Prakash said.

The state will also challenge the tribunal order which had asked it to release four tmc ft of water to compensate the loss of water that flows into sea, he said.

Thursday's decision might help the state ease the ongoing protests against the award in the Cauvery basin districts of Mandya and Mysore besides the city.

It was also likely to help the government to take the wind out of the sails of the opposition parties, which have been attacking it for failure to pronounce its stand on the tribunal order.

Prakash, however, declined to spell out details on the prayers the state would make in its original petition and SLP.

"It would be conveyed to our lawyers and then to the press," he added.

"There are several legalities involved in it, which can't be disclosed at this stage", he said.

Prakash said since the compilation of the original suit would take some time, the state would file a SLP before the Supreme Court and later file the petition before the tribunal for clarificatory orders.

The state was required to file petitions before the tribunal seeking clarifications within 90 days of the pronouncement of the final award.